Successful Treatment of Corticosteroid with Antiviral Therapy for a Neonatal Liver Failure with Disseminated Herpes Simplex Virus Infection

Case Report: Rapid Recognition and Immune Modulation of Secondary HLH Due to Disseminated HSV Infection

We describe the case of a newborn who presented with multiple organ dysfunction syndrome (MODS) and hyperferritinemia, who eventually met criteria for hemophagocytic lymphohistiocytosis (HLH) due to disseminated herpes simplex virus 1 (HSV-1). While the cytokine storm abated after administration of multiple immune modulatory therapies including dexamethasone, etoposide, intravenous immune globulin, anakinra, as well as the interferon gamma antagonist emapalumab, multiple organ dysfunction syndrome progressed. Care was withdrawn after 5 days. Subsequent genetic testing did not reveal any mutations associated with familial HLH. This case highlights that even with appropriate antiviral treatment and immune suppression, disseminated HSV is often fatal. Further study is warranted to determine whether early immune modulatory therapy including interferon gamma blockade can interrupt the HLH inflammatory cascade and prevent progression of MODS.

Challenges in the diagnosis of hemophagocytic lymphohistiocytosis: Recommendations from the North American Consortium for Histiocytosis (NACHO)

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of pathologic immune activation, often associated with genetic defects of lymphocyte cytotoxicity. Though a distinctive constellation of features has been described for HLH, diagnosis remains challenging as patients have diverse presentations associated with a variety of triggers. We propose two concepts to clarify how HLH is diagnosed and treated: within the broader syndrome of HLH, "HLH disease" should be distinguished from "HLH disease mimics" and HLH subtypes should be categorized by specific etiologic associations, not the ambiguous dichotomy of "primary" and "secondary." We provide expert-based advice regarding the diagnosis and initiation of treatment for patients with HLH, rooted in improved understanding of its pathophysiology.

Critically Severe Case of Neonatal Herpes with High Viral Load and Hemophagocytic Syndrome

Neonatal disseminated herpes simplex virus (HSV) infection is a severe disease with high mortality and morbidity; yet, the pathophysiology remains unclear. Here, we report a male infant with disseminated HSV type 1 (HSV-1) infection, complicated by hemophagocytic lymphohistiocytosis (HLH) and multiple organ failure. The infant, born at 39 weeks of gestation by normal delivery, developed fever (38.5˚C) with the high serum C-reactive protein levels on the 1st day of life, and exhibited tachypnea on the 3rd day. On the 5th day of life, the patient received mechanical ventilation and was transferred to our neonatal ICU. Real-time PCR for HSV-1 DNA revealed an extremely high serum concentration (1.0 × 10⁹ copies/µL), and he was diagnosed with HSV-1 infection. Acyclovir (ACV) and corticosteroid pulse therapies with methylprednisolone were started. Continuous hemodiafiltration (CHDF) using cytokine-absorbing hemofilters was also initiated because of renal failure. These therapies, however, failed to control the disease, and the patient died on the 41st day of life. The dose of ACV on CHDF might not be adequate, although we could not measure the serum ACV concentrations. After the patient's death, we measured his serum cytokine concentrations taken four times during the clinical course. Serum concentrations of interleukin (IL)-6, IL-10, IL-1β, and interferon (IFN)-γ were elevated at the time of admission and were remarkably decreased by 10 days after treatment. In particular, the concentrations of IL-1β and IFN-γ were lower than the measurable ranges. It is therefore important to measure serum cytokine concentrations in real time to prevent excessive immune suppression.